Digital video, in summary, comprises a plurality of digital images or video frames. Due to the large amount of data generated by digital video, compression is often performed. MPEG video compression is a popular technique. In MPEG, each video sequence is divided into one or more groups of pictures (GOP). Furthermore, each GOP is composed of one or more frames of three different types: I-frames, P-frames, and B-frames. I-frames (intra-coded frames) are coded or otherwise compressed independently, i.e. without reference to other frames. P-frames are compressed by coding the difference between the current frame and a temporally preceding I-frame or P-frame. B-frames do not have bearing on the methods or devices described herein.
In general, lossy video compression methods, such as MPEG, introduce artifacts into the individual video frames. In some applications, it may be desirable to extract a single frame from the video sequence, enhance its quality, and save this single frame as an independent image. However, the artifacts introduced by these lossy compression methods can significantly reduce the image quality.